(a) Field of the invention
The present invention relates to a novel alloy, useful particularly in dentistry.
(b) Description of the Prior Art
Two types of porcelain are used to form artificial teeth or parts thereof to fix to abutments (fashioned stumps) of natural teeth in the patient's mouth. These two types are aluminous porcelain and feldspatic porcelain. Aluminous porcelain is generally regarded as superior, in matching the look of live teeth, in being more workable, in being stronger and in being not as hard. The hardness of aluminous porcelain is more like that of natural teeth and hence in use it does not abrade natural teeth as much as feldspatic porcelain. Aluminous porcelain is thus much used for cementing directly to abutments by means of a cement.
Feldspatic porcelain, however, is used for bonded work. That is to say in the case where the porcelain is fused to a cast metal substructure, thereby effecting a bond between the two materials, and the substructure is then cemented to the abutment. Feldspatic porcelain is little used for non-bonded work because of the superiority of aluminous porcelain.
On the other hand, aluminous porcelain is not used for bonded work because there is no metal known from which there may be formed a compatible cast metal substructure. Thus, while aluminous porcelain would be preferred for bonded work were there to be a metal known from which a compatible cast metal substructure could be formed, no such material is known. There is, therefore, a need for a metallic material for use in forming such substructures.